Type bar actuating mechanism for typewriting machines



0a. 29, 1963v E. v. BYERS 3,

TYPE BAR ACTUATING MECHANISM FOR TYPEWRITING MACHINES Filed Feb. 5. 1960 EDWA m: V/c r0)? Brim /NVIV70R ATTORNEYS United States Patent 3,108,674 TYPE BAR ACTUATING MECHANISM FUR TYPEWRITING MACHINES Edward Victor Byers, 16 Barrack Lane, The Park, Nottingham, England Filed Feb. 5, 1960, Ser. No. 7,015 4 Claims. (Cl. 197-27) This invention relates to a method of actuating the type bars in typewriting machines of the kind in which the type bars are pivotally mounted around a circular arc and arranged to strike at a common center against a platen carrying the paper or other medium upon which the typed impression is to be taken, and in which each type bar can be caused to deliver a printing stroke by the manual operation of a key on a keyboard situated at the front of the machine.

Such machines are, most usually, provided with a keyboard in which the keytops are secured to the ends of horizontally disposed levers pivotally mounted at points in rear of the keyboard in such a manner that the length of the levers is long in relation to the keytop stroke desired, the latter being, thus, substantially vertical. Transmission of the motion of the key levers to the type bars is commonly effected by various systems of links and intermediate levers. This invention has, as its object, the provision of a transmission system in which only a relatively small number of parts is required.

According to this invention the movement of the finger operated keys is transmitted to the type bars by members consisting in part of a flexible cord or wire which passes around or along suitable guides so that the movement of the finger operated keys effects a longitudinal movement of the members to operate the type bars. The end of the flexible cord or wire is connected directly to the finger operated keys which may be levers or longitudinally movable slides.

The invention will now be more particularly described with reference to the accompanying drawings in which:

FIG. 1 is a sectional side elevation and FIG. 2 a plan showing type bar operating mechanism constructed according to this invention.

FIG 3 is a rear elevation of the finger operated keys shown in FIGS. 1 and 2.

FIG. 4 is a plan of the flexible tension member provided to connect the finger operated keys to the type bars.

Like numerals indicate like parts throughout the drawmgs.

The main feature of the mechanism lies in the use of a flexible tension member in the connection between the finger operated keys and the type bars, any required change in direction of the path followed by .the flexible tension member between its ends being obtained by leading it over a guide or guides which are fixed in relation to the frame of the machine. Accordingly, each type bar 1 is provided near its main pivot 2, with means for pivotally attaching one end of a flexible tension member 3 consisting in part of a flexible cord 4 made of a material such as nylon, the relationship of this member 3 to the main body of the type bar 1 being such that the type bar is caused to swing to the printing position when the cord 4 is pulled in a suitable direction governed by the general considerations of design. The cords 4 are arranged to pass over fixed smooth guides, or along grooves 5 provided for the purpose in the frame 6 or over pulleys (not shown), and, thence, to pivotal attachments on the appropriate finger operated keys. The possible positions of the direction changing guides depend upon the relative desired locations of the finger operated keys, and slotted plate or segment 7, in which the type dfldhfild Patented Got. 29., 1:963

bars 1 are mounted. In machines in which the segment 7 is to be movable, to provide two cases of type impressions, the guides are to be so located that the cords 4 remain initially taut in both rest positions of the segment 7.

The shock which would otherwise be experienced at the beginning and end of the keytop stroke may be absorbed by incorporating springs or other resilient members (not shown) somewhere in the length of the cords 4.

Similar type bar actuating means may also be used without having recourse to pivotally mounted key levers, as in the construction shown in FIGS. 1 and 2 by mounting the keytops 8 on key rods 9 which are arranged to slide in holes or sockets 10 provided in a suitable chassis or as shown in FIGS. 1 and 2 in the frame 6 of the machine. The cords 4 are then arranged to be trained along grooves 5 extending from the tops of the holes 10 in the chassis, or frame 6, the cords 4 then lying along the sides of the said key rods d, and being secured to the bottoms thereof. In machines in which the segment 7 is fixed, there grooves 5 may be used as the only direction changing device for the cords 4, especially if a varying angular working stroke of the type bars 1 at different positions in the segment 7 be acceptable.

The flexible tension members 3 connecting the type bars 1 to the finger operated keys also include a rigid tube 17 of suitable length having the flexible tension member 4 passing therethrough, the ends of the tube 17 being nipped to grip the flexible tension member 4 and the ends of the flexible tension member 4 connected, respectively to a type bar 1 and finger operated key rod 9. In the preferred construction shown in FIG. 4 each connecting member 3 is moulded from nylon and comprises a thickened relatively rigid part 11 having a hook 12 at one end to engage in a hole provided for the purpose in the type bars 1 and a flexible cord-like tension portion 13 at the other end which is connected to a cross piece 14. The key rods 9 are preferably rectangular to prevent them from turning in the sockets 10 and the cross pieces 14 engage in slots 15 provided for the purpose in the key rods 9 as shown in FIG. 1.

In order to return the finger operated keys to their normally raised positions after being depressed leaf springs 16 are provided. These leaf springs 16 are provided with fork shaped ends through which the cords 4 pass, the springs engaging with an abutment on the member 3 which may conveniently be the end of the thickened part 11 shown in FIG. 4. As will be readily apparent from FIGURE 1, each leaf spring 16 reacts against the chassis 6 and the thickened portion of the respective flexible tension member 3. In the showing of FIGURE 1, the leaf spring 16 reacts against a tube 17. When the flexible tension member of FIGURE 4 is utilized, the leaf spring 16 reacts against the thickened portion 11. It will be apparent that the reaction of each leaf spring 16 against its respective flexible tension member 3 is such that the flexible cord like portion thereof is tensioned to lift the respective key rod, and at the same time the thickened portion is placed in compression and forces the associated type bar 1 to its normally lowered position. FIGURE 1 shows the stop member 18 against which the type bars 1 are held by the spring 15. Each tension member 3-, by having a portion thereof in tension and a portion thereof in compresison, permits a single spring to serve the dual function of lifting the associated key rod 9 and lowering the associated type bar 1.

What I claim is:

1. In a typewriter including a chassis having a type bar segment and type oars pivoted in the type bar segment, a plurality of vertical sockets formed in said chassis, a key rod freely slidable in each socket, a finger engageable key top on the upper end of each key rod, a guideway in said chassis associated with and opening into each socket, a flexible tension member for each key rod connected at one end to the respective key rod and at the other end to a respective one of the type bars, each of said tension members having a relatively rigid portion connected to the respective type bar and being capable of transmitting a compressive force, and a return spring for each key rod connected between the chassis and said rigid portion and reacting against both said chassis and said rigid portion to simultaneously tension the portion of said flexible tension member attached to the key rod to lift the associated key rod to its normally raised position and exert a compressive force on said rigid portion to return the associated type bar to its normally lowered position.

2. The type bar operating means of claim 1 wherein said return spring is a leaf spring having one end anchored to the chassis and the other end engaging over said tension member and abutting against the end of said rigid portion remote from the respective type bar.

3. The type bar operating means of claim 1 wherein each of said tension members is of a onepiece molded construction having a hook at the terminal end of said rigid portion engaging the respective type bar and a terminal cross piece for engagement with a respective key rod.

4. In a typewriter including a chassis having a type bar segment and type bars pivoted in the type bar segment, a plurality of vertical sockets in said chassis, a

.4 key rod freely slidable in each socket, a finger engageable key top on the upper endof. each key rod, a guideway in said chassis associated with and opening into each socket, a flexible tension member for each key rod connected at one end to the respective key rod and at the other end to a respective one of the type bars, each of said key rods having a vertical slot therein and a lower transverse slot intersecting the vertical slot, each tension member having a terminal cross-piece anchored in said transverse slot and an end portion extending through said vertical slot to said guideway, and, each of said tension members having a relatively rigid portion connected to the respective type bar and being capable of transmitting a compressive force, and a return spring for each key bar connected between the chassis and said rigid portion and reacting against said chassis and said rigid portion; whereby each of said tension memhers is placed partially in compresison and partially in tension and operates to return its respective type bar to its normally lowered position and to also return its respective key rod to its normally raised position.

References Cited in the file of this patent UNITED STATES PATENTS 722,291 Ferguson Mar. 10, 1903 1,058,688 Myers Apr. 8, 1913 2,301,112 Erbs Nov. 3, 1942 FOREIGN PATENTS 358,204 Germany Sept. 7, 1922 

1. IN A TYPEWRITER INCLUDING A CHASSIS HAVING A TYPE BAR SEGMENT AND TYPE BARS PIVOTED IN THE TYPE BAR SEGMENT, A PLURALITY OF VERTICAL SOCKETS FORMED IN SAID CHASSIS, A KEY ROD FREELY SLIDABLE IN EACH SOCKET, A FINGER ENGAGEABLE KEY TOP ON THE UPPER END OF EACH KEY ROD, A GUIDEWAY IN SAID CHASSIS ASSOCIATED WITH AND OPENING INTO EACH SOCKET, A FLEXIBLE TENSION MEMBER FOR EACH KEY ROD CONNECTED AT ONE END TO THE RESPECTIVE KEY ROD AND AT THE OTHER END TO A RESPECTIVE ONE OF THE TYPE BARS, EACH OF SAID TENSION MEMBERS HAVING A RELATIVELY RIGID PORTION CONNECTED TO THE RESPECTIVE TYPE BAR AND BEING CAPABLE OF TRANSMITTING A COMPRESSIVE FORCE, AND A RETURN SPRING FOR EACH KEY ROD CONNECTED BETWEEN THE CHASSIS AND SAID RIGID PORTION AND REACTING AGAINST BOTH SAID CHASSIS AND SAID RIGID PORTION TO SIMULTANEOUSLY TENSION THE PORTION OF SAID FLEXIBLE TENSION MEMBER ATTACHED TO THE KEY ROD TO LIFT THE ASSOCIATED KEY ROD TO IS NORMALLY RAISED POSITION AND EXERT A COMPRESSIVE FORCE ON SAID RIGID PORTION TO RETURN THE ASSOCIATED TYPE BARE TO ITS NORMALLY LOWERED POSITION. 